/Engine/Source/Editor/PropertyEditor/Public/DetailLayoutBuilder.h
To access StaticArray at index 2 from Struct2 in MyActor, your path would be MyStruct.StaticArray[2]" and your instance name is "Struct2"
 To access MyFloat in MyActor you can just pass in "MyFloat" because the name of the property is unambiguous
[TSharedRef](API\Runtime\Core\Templates\TSharedRef)< [IPropertyHandle](API\Editor\PropertyEditor\IPropertyHandle) > GetProperty ( const [FName](API\Runtime\Core\UObject\FName) PropertyPath, const [UStruct](API\Runtime\CoreUObject\UObject\UStruct) * ClassOutermost, [FName](API\Runtime\Core\UObject\FName) InstanceName ) const